The present invention relates to a novel compound, a prostaglandin I analogue, which is referred to as PGIs simply hereinafter.
It has been well known that PGI.sub.2 has a platelet aggregation controlling effect and a hypotensive activity, but it simultaneously has some side effects such as increasing of pulse rate, hot flush, abdominalgia and the like (S. M. M. Karim et al, PG. Med., 9, 307(1982)).
Japanese Patent Application KOKAI No.61-78734 discloses an effectivity of tricarbonyl-aromatic-group VIB metals complex as a catalyst for reduction of .alpha.,.beta.-unsaturated carbonyl compound, and the production of {(1S,2R,3R,5S)-(E)-7-(4-carbomethoxybutylidene)-2-(3-oxooctyl)-3-tetrahydr opyranyloxy-bicyclo[3.3.0]octane} by the reaction of {(1S,5S,6S,7R)-3-(4-carbomethoxy-1(EZ)butenyl)-6-(3-oxo-(E)-1-octenyl)-7-t etrahydropyranyloxybicyclo[3.3.0]octane} in the Example 7. Further, Japanese Patent Application KOKAI No. 61-37740 disclose the same compounds as the above in the Example 7. However, any prior arts as referred do not disclose the PGIs (I) and (II) of the present invention, and any usefulness thereof.